Zur Synthese von Motilin, I. Darstellung der Sequenzen 9-22 von [13-Norleucin]motilin und [13-Leucin] motilin

Abstract
The syntheses of 2 suitably protected tetradecapeptides corresponding to the sequences 9-22 of [13-norleucine]motilin [H-Glu(OBut)-Leu-Gln-Arg(HBr)-Nle-Glu(OBut)-Glu(OBut)-Lys(Boc)-Glu(OBut-Arg(HBr)-Asn-Lys(Boc)-Gly-Gln-OBut] and [13-leucine]motilin, respectively, are described. The 2 building blocks for the total syntheses of the intestinal hormone motilin analogs were obtained by fragment-condensation of smaller units, prepared by stepwise procedure and corresponding to the sequences 18-22, 14-17, 12-13 (norleucine- and leucine-derivatives) and 9-11.